Michael Williams's Unnatural Doubts: Epistemological Realism and the Basis of Scepticism offers us something I would not have imagined possible before reading it: a genuinely novel, and very powerful, line of argument against epistemological skepticism. It also purports to show that competing antiskeptical arguments fail. I am enthusiastic about the new antiskeptical weapon that Williams has added to our arsenal, but dubious about his claim that the weapons previously on the market were ineffective. So I shall first try to show off Williams's new weapon in the most advantageous possible light. Then I shall argue that Williams has not shown that there is anything wrong with the alternative weapon purveyed by Donald Davidson, one of his principal competitors in the antiskepticism business. Finally, I shall argue that, although Williams's and Davidson's weapons embody the same basic design, there are reasons for preferring Davidson's version.

Barry Stroud, the leading contemporary exponent of the view that epistemological skepticism is a serious and important issue, says that skepticism “appeals to something deep in our nature.” Stroud tries to show “how closely Descartes’ requirement that the dream-possibility be eliminated corresponds to our ordinary standards or requirements for knowledge in daily life.” He claims that “the sources of Descartes’ requirement. … illuminate something about our actual conception of knowledge.”

Williams rejoins that we do not have an “actual conception of knowledge” to be illuminated. Williams thinks that there is no such thing as “human knowledge” or “our epistemic position” or “our view of reality.” As he puts it, there may be “fewer things in heaven and earth than are dreamt of in our epistemology” (102).